Feliks Audio is a family company based out of Lubliniec, Poland. Their specialty –tube amps. Many will already be familiar with their fabled Elise, but few may know about its older sibling, the Espressivo. Overshadowed in a sense by its overachieving younger brother, the Espressivo has more or less faded into anonymity. It’s not particularly hard to see why the Espressivo never went mainstream –it is an understated amp with little by way of features or specifications. However, looking past these modest characteristics, one will find an amplifier that is nothing short of a hidden gem. Coming in at a modest $ 349.00 USD (the shipping/ import fees might set you back some), the Espressivo sounds plain excellent with the right cans –and frankly it could’ve been priced higher. It’s an exacting mix of musicality and dynamism that makes for an amplifier worthy of commendation.​

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Disclaimer​

The Feliks Audio Espressivo was provided directly from Feliks Audio for the purposes of this review. I’ve been told that I can keep it due to the expensive back and forth shipping costs (I do appreciate it) and have now had it on hand for slightly over three weeks. I am neither a paid affiliate nor an employee of Feliks Audio. In addition, I do reserve the rights to the media used in the review, so do contact me if you wish to reproduce any part of the writing or photography seen here. Apart from that, I thoroughly enjoyed this amplifier and hope that y'all like this review. It can also be found on my blog here. Apologies to those who chanced upon this review in its early stage, I accidentally clicked enter twice, causing the form to submit before I was done moving everything over from Word. ​

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PACKAGING AND ACCESSORIES​

The Espressivo arrived in a good-sized cardboard box. The only indication of it being a Feliks Audio product was the tape on the front, which carried the company name and logo. Opening up the box, I found the amplifier encased in large Styrofoam blocks and marshmallows. There’s a short user’s manual and the 4 included tubes. For my package, I did happen to receive two extra sets of tubes –the 6N5P and the 6N1P-EW. The Feliks Audio amp is built-to-order and since it isn’t a huge operation, usually has a lead-time of a week or two. The wait though is completely worth it.​

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BUILD AND DESIGN​

The Espressivo is larger than it looks in the photos. Opening it up, I realized that this would take up more desktop space than I had been ready to make available. It was heavy too. The design of the Espressivo is very nice. It’s got wood accent panels on the sides that come in three colors: alder, brown, and black (pictured is the brown version). There’s a nice grain to the wood and it definitely feels high quality. The rest of the amplifier is metal. Placed at the front are tubes (stock – 6N1P & 6N6P) and at the rear the toroidal transformer enclosure. Once of the things that I did note was that the price and tube setup of the Espressivo is identical to that of the Schiit Valhalla. I don’t have the latter on hand, so I’ll leave that thought here –maybe a Valhalla owner could chime in.​

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The volume pot is heavy and well built. The indicator is a small black notch at the flare of the pot, which is hard to see in dimly lit conditions. The dial markings are a nice touch, and make it easy to find one’s way around (would’ve been even better with markers at the cardinal points). The font on the front panel is little weird and slightly too big, but it’s not intrusive enough to be a major aesthetic issue. Next to the volume pot is the input selector, which has a nice tactile feel to it. The rear panel features three line-inputs, and one pre-amp out. Directly to the right is a nice large power switch to turn the unit on and off. Overall, it’s an understated but fairly elegant design, and certainly looks nicer than many of its similarly priced counterparts.​

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TECH AND SPECIFICATIONS​

At the heart of the Espressivo are two sets of NOS tubes. Stock 6N1Ps act as driver/pre-amp tubes, and can be safely replaced with E88CC, 6N23P, 6DJ8, and 6922. I’ll add to that the 6N5P and the 6N1P-EW. The power tubes are the 6N6P, and the only recommended alternative is the 6N6P-1. There’s no exact output impedance printed on the manual, so I decided to ask the team at Feliks Audio –who subsequently responded that it is slightly under 100 ohms. The first thought that came to mind was how this would affect the damping factor and interactions with different cans. The RMAA may be informative in this sense. ​

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I guess the following could almost become a disclaimer of sorts. RMAA results are only as good as the equipment used to perform the tests, and there has been a decent amount of coverage on its limitations and weaknesses. Consider it as a broad proof-reading of published technical specifications. I’m ranging THD readings from 0.041 – 0.052 range, and an intermodulation distortion (plus noise) of around 0.042% for the Espressivo. Currently, I am utilizing an Asus Xonar U7 external sound card (line-in mode). The ADC is a Cirrus Logic CS5361-KZZ that is capable of 24/192 w/ a 114 dB dynamic range. It uses a 5th order MBT Delta-Sigma Modulator, and attains low levels of noise and distortion. For those curious, the DAC is the equally capable CS4398-CZZ. Please find my results below. After reminder - the 470 ohm load is the R70X, and the 39 ohm load is the MH40.​

-65NP is the the topmost graph (blue) and the one that is behaving slightly differently.​

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Stock 6N1P Tubes (39 Ohm Load) - Not So Good ​

SOUND​

At A Glance​

The Espressivo is a musical amplifier. Looking at specs alone, it’s not going to be able to compete on the same technical level as certain other amplifiers. But, let’s put that aside for a second, and talk about subjective sound impressions. I’ll start by throwing this out there –I do have a slight penchant for cleaner, more analytical sounding gear. It’s one of the reasons why I’ve come to appreciate the ER4 as my primary use IEM. But at the same time, there are occasions where I do feel a tilted signature is worthy and in some instances, even more desirable –hence the TH-900. The Espressivo is one of those instances –a fine example of musicality done right and overall, an impressively exciting sound with great dynamism. Without a doubt the Espressivo needs to be paired correctly. The high output impedance may make for unfavorable interactions, especially with lower impedance headphones. On a related note, noise floor is also rather noticeable with high sensitivity gear.​

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Soundstage And Imaging​

Alright, let’s get this out of the way. The Espressivo does many things right, but soundstage isn’t exactly one of them. With certain tracks, I felt that the width of the soundstage was limited. The Tao Of Love by Vangelis is one such piece. In the past, I have used it as a showcase example of the T1’s ample soundstage and panning capabilities. However, with the Espressivo, I felt that the sound had been clipped on the sides, making for a width that was narrower than expected. Height is okay, but nothing particularly noteworthy. The Espressivo does however offer excellent depth, and this came through with orchestral works. Imaging is similarly good, and there’s a surprising amount of separation and air. This is a strength that works well with the lower frequency performance to provide for a fairly fast and exciting sound.​

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Bass​

The Espressivo has a bass boost –and a very satisfying one at that. It peaks in the subbass region and slopes nicely into the midbass. It’s a fairly clean boost that adds more to the presence than raw quantity of the lower-end. I found that it had a wonderful synergy with the T1, loosening up the occasionally restrained bass while still maintaining a positively responsive sound. The overall result was a much more visceral low-end, one that really made for an involved listening experience. You’ll hear it on tracks like La Cathédrale Engloutie by Debussy (interpreted/played by Jean-Efflam Bavouzet). Certainly, the climax (sonore sans Dureté) was impressive, but it was in fact the opening (peu à peu sortant de la brume) that got my attention. The way the mysterious emergence of the castle from the ocean was captured through the deep bass was very impressive, and it did feel like I was staring into the very depths of the ocean. ​

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Mids​

The mids are connected nicely into the overall sound. Perhaps, a little less immediately striking than the bass or highs, but not disjointed or overly recessed by any standard. There is good body behind the mids and its strongest aspect lies in the upper-mids, where I found great energy and richness. A seamless transition into the highs followed. I thoroughly enjoyed listening to Bossa Nova tracks like the Girl From Ipanema, and found that the vocals had a slightly sweet nature while still maintaining a good textural quality. ​

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Treble​

The highs are very enjoyable on the Espressivo. It’s fluid and has a very nice sparkle, and is one of the reasons why the amplifier excels in terms of musicality. However, it also has the tendency to get slightly hot, especially on modern and less well-recorded tracks. On Breath Your Name by Sixpence None The Richer, a small amount of sibilance started to come through, and the sonic portrayal got a little intense midway through the piece. At the same time that I want to say that this needs to be toned down a tad, I did find it strangely addictive. User mileage may vary I suppose.​

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Short Notes On Tube Rolling​

So in addition to the 6N1P, I did receive the 6N1P-EW and the 65NP for assessment. I’ll start with the 65NP. I did notice that with the 65NP that the lower and higher frequencies got a slight boost. Generally speaking, there was a little more sibilance on certain tracks, and at the times it did push the Espressivo too far, bringing it into the hotter side of things. I also felt that the sound from the 65NP was detached, especially around midrange, and it just generally wasn’t as good a listen. The 6N1P-EW is an extended life, military grade tube based on the limited background information I was able to find on it. Sonically, it boasted similar characteristics to the stock 6N1P. Perhaps the only notable difference was slightly less bass and a subtle increase in highs. Overall, of the three that I had an opportunity to try, I felt that the stock tubes did the trick and there wasn’t a pressing need to switch them out.​

FINAL THOUGHTS​

The Espressivo is oodles of fun. It's got an engaging sound signature featuring great dynamism and musicality. The end result is nothing short of a very "big" sound. The build quality is plain excellent, and feels like something fitting for a far more expensive product. Frankly, at a price of 349.00 USD, there's little reason why not to give this amplifier a try, especially if you've suitable high-impedance cans. It's an exciting listen, and when paired with the right cans can really make them sing. If you're in the market for a musical amplifier and have the said higher impedance headphones, I would heartily recommend the Espressivo. It's really good!​

Hi @thatonenoob, I was wondering what you think about the synergy of the Espressivo with the Sennheiser HD600s. But first I'd like to give you a bit of context, so please excuse me for the long post.

I just entered the head-fi game after a long time lurking period, buying a pair of Sennheiser HD600s from another Head-fi member. Now I'm looking into buying an entry level amp for them, albeit having next to none listening experience with headphones (except owning a pair of Etymotic Hf2s for quite some time now). At first I was looking to merely get a glimpse into the game, e.g. either by opting for an O2+ODAC or picking up a Little Dot MkIII and play around with tube rolling. Then I came across Feliks Audio and their seemingly knowledgeable and visually gratifying work, and I developed an appetite to expand my initial budget of around $200-250. Nevertheless, the cost of the Espressivo is the limit—and only if it makes up for the asking price; unfortunately I cannot afford the Elise.

Feliks audio also brings forth the question between going for solid state or tubes. Having read a lot about OTL realizations such as the Bottlehead Crack, it seems that the Senns actually pair nicely with tubes. In spite of the fact that I come from a solid state background (I also own an audiophile grade system build around a pair of ATC SCM20s and the ATC SIA-2 150 integrated) I also have a very fond memory of a tube based system which was very intimate, holographic, and overall greatly appealing. Therefore, having the ATC system at home, I wanted to take the opportunity with the Senns to experiment towards finding that sound anew. Truth be told, that system was a very good one; if my memory serves me, it was a pair of Red Rose music speakers (Mark Levinson design) on an Audio Research set of pre & power amp (so, lots of $$$)! Ever since that time, I've had the opportunity to listen to tube systems on many occasions; but apart from the occasional exotic gem (e.g. Lamms) I never grew entirely fond of them—or at least I never found the sound that exited me so much that one time.

In addition, I'm also worried that the HD600s will reflect/reveal greatly upon the signature of the amp. I have suffered the same with my ATCs, for which I ended up paying a good deal of money in order to satisfy [their] appetite. Having this experience, I'm afraid that the same applies with the Senns. That aspect alone might make the case to stop looking into tubes, unless I'm able to churn out a substantial amount of money.

I've enjoyed your review immensely, and this is why I'm asking for your advice. Once again let me apologize for the long post, but I wanted to make my case as clear as possible.

First of all, I'd like to say — Espressivo-E looks really great. Not so many "major" brands makes such nicely looking amps. Great combination of black metal and wood makes amp looks very luxury. It can not only power your headphones, but also decorate your room.

Amp build using 4 Sovtek tubes, and does it's best to show main good points of tube sound: lively mids, musical sound and great resolution. Lows are nice, full-bodied and puchy. Highs are little bit relaxed, but I like this, as it makes sound not so fatiguing.

Espresivo is a nice companion for most of headphones (except the toughest ones), and even drives AKG K702 really good.

It can be purchased from FeliksAudio.pl (makers of this amp) or from ebay.co.uk

Cons - Slightly too rounded treble, a bit to loose in bass control with bassy headphones.

Very nice amplifier. Very solid build. Love vocal presentation and rich lower mids. Helps to achieve warm signature with technical headphones like T70 (even with such effective headphones there is no hum..). Perfect partner for HD650. Works good with K701. 3 pairs of inputs make it very versatile machine. Price is rather attractive (about 160 Euro) for the unit made and designed in EU - bergain. Equipped with 4 x SOVTEK tubes.

Firstly I would like to thank Lukasz at Feliks Audio for sending me this amp to review, I did not get this amp as a free of charge sample, I had to pay for the unit as I liked it so much I wanted to keep it. I try and write honest reviews.
The stock tubes have been fully burnt in with over 100hrs through them.

Packaging, Accessories and Build quality:
The amp came in a large card box, inside this are foam cut outs that hold the amp securely in place. A power cord is included, and there was a manual and separate cut out for the valves, which are individually numbered and wrapped in foam. The amp is very securely held in place in transport and the packaging is well thought out.

Accessories, well this comes with all that is needed, valves and power cable, they include the correct power cable for the country you ordered from, which is a good. I cannot think of any needed accessories for this amp.

Build quality feels very good, the main chassis is sturdy metal, the underside feels a little thin but once it is sat on a shelf you won't notice this. There are wooden side panels which give it a very appealing look, the finish isn't that of a high end piece of equipment, but it sure adds some class and elegance to the amp. The input and output sockets on the back are gold plated, the volume knob and input selector knob all feel of high quality and the jack output is nice and snug. The tube sockets are also nice and tight, I cannot fault the build for the price, I couldn't fault it even if it cost a little more.

Functionality:
Well this is a very versatile amp, it has 3 inputs (I use it for DAC from pc/CD, iPod and turntable (after preamp) to the one output to my amp, or I use the headphone socket for headphone listening. So it can be used as a pre-amp as well as a headphone amp. As with all valve amps, it takes 15 minutes or so to warm up, I have left it running for periods of 8 hours and more, the valves get very hot, the chassis does a good job at dissipating the heat and I never felt like it got dangerously hot.

Valve rolling is easy with the driver tubes, the power valves are not as easy to find alternatives. The driver valves are 6N1P and can be replaced by E88CC / 6N23P / 6DJ8 / 6922.
The power valves are 6N6P and can be replace with 6N6P-1.

Sound:
Well valve amps are usually chosen for their introduced distortion which adds a little flavour to the sound, and also for looks and valve rolling capabilities to tune the sound to your taste.

I personally enjoy the sound valve amplifiers can produce, and also I like the aesthetics.

Upon first listen I was very surprised to find that this valve amp is very detailed and doesn't change the sound too much. Remembering my Xduoo TA-02 with Mullard valves, that was a very lush and warm sounding amp that was a pleasure to listen too, but maybe a little too polite.
The Espressivo on the other hand has the speed and detail to keep up with most solid state amplifiers, yet still has a touch of warmth which helps liven up certain flat or otherwise boring sounding headphones.

Valve rolling possibilities are very good with this amp, so you can easily buy other valves to help fine tune the sound, and making it warmer or more analytical depending on what you want. The base design of this amp is fantastic, and even stock, it sounds very natural and effortless with good speed and detail.

I find the separation to be very good, however the soundstage is not hugely different over an objectively flat amplifier.

What I like about this amp, is that It can drive most headphones very easily, it is not the best for sensitive in-ear monitors due to the relatively high gain, but for over-ear headphones it works very well. The GMP400 are relatively hard to drive yet I only have the volume on the 9-10 o'clock position. I recently took this amp to CanJam London and it was driving the T1 with no problems and sounded incredible with them.

The Espressivo + T1 are a fantastic home listening combo that will set you back about £1000, it is funny how you can get a £200 amp that really brings the best out of the T1.

I find the sound of the Espressivo engaging and articulate, it still has micro detail but the overall sound is enjoyable rather than analytical. The sound is also effortless with a good amount of power on tap, no need to worry about this amp under powering your headphones. A very impressive hand built valve amp, for an incredibly reasonable price, it also looks lovely.

THE Marshall Jefferson, enjoyed listening to this amp so much at CanJam he went out a placed an order straight away.